Charles e



(No Model.)

0. E. SORIBNER. APPARATUS FOR TELEPHONE SWITGHBOARDS.

No. 554,399. Patented Feb. 11, 1896.

lTzlyEjSsES LNVENTOR,

W14 C'imrlwlii 50222 new;

UNITED STATES LATENT OFFICE.

CHARLES E. SCRIBNER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE WESTERNELECTRIC COMPANY, OF SAME PLACE.

APPARATU 8 FOR TELEPHON E-SWITCH BOARDS.

SPECIFICATION forming part of Letters Patent No. 554,399, dated February11, 1896. Application filed July 2,1895. Serial No. 554,701. (No model.)

To all whom, it may concern: it, and at the same time to obtain itsadvan- Be it known that 1, CHARLES E. SCRIBNER, tages to acertain extentin all connections. a citizen of the United States, residing at Chi- Theinvention consists in providing for cago, in the county of Cook andState of Illieach line upon that section of the switch- 55 nois, haveinvented a certain new and useful board which contains theline-annunciator a Improvement in Apparatus for Telephonespecialspring-jack having such separable Switchboards, (Case N o. 392,) ofWhich the switch-contacts, these switch-contacts being following is afull, clear, concise, and exact included in thetelephone-line at thebegin description, reference being had to the acning of the system, sothat when separated 6o 10 companying drawing, forming a part of thisthey disconnect the main line from the appaspecification. ratus in theremainder of the switchboard. My invention concerns the circuits and theThis spring-jack may preferably be the anarrangement of spring-jacks oftelephoneswering-jack in the switchboard-that is, a lines in multipleswitchboards of the branch spring-jack distinct from the line spring- I5 terminal type, being a device for dissociating jacks in the samesection of the switchboard from the line its shunting-annunciator orsigand located at some easily-accessible point nal-indicator, togetherwith the cable through after the manner of Patent No. 330,067, datedthis instrument, and for permitting complete November 10, 1885, to J A.Seely. Hence or thorough connections between different when connectionis made with any line at the 20 lines to be made under certaincircumstances answering-jack, in response to an initial sigwithoutleaving any unnecessary instruments nal from the subscriber, theline-annunciator or cables appended to the lines. of that line, togetherwith thecables extend- In multiple telephone-switchboards of the ingthrough allother sections of the switchtype mentioned the spring-jacks011 the differboard, is disconnected from the outgoing line. 7 5 25 cutsections of switchboards are connected in Usually the connection will becompleted at multiple with the line, while the signalingthe same sectionof switchboard with a line instrument or line-annunciator is placed in ajack of another line, so that the cables and permanent bridge of theline-circuit. The annunciator of the latter line will still remainannunciator is constructed to have high reconnected with it and willbecome useless apo sistance and impedance to prevent, as far as pendagesto the completed circuit; but a conpossible, the shunting of telephoniccurrent siderable advantage is attained by thus disthrough it. Onaccount of the imperfection connecting from even one of the lines theunwith which this function was exercised in necessary cabling andapparatus. I cases where very long or high resistance-cir- Each sectionof switchboard is furnished 8 5 3 5 cuits were coupled together it hasbeen cuswith trunk-lines or transfer-circuits extend tomary to provideat the beginning of the ing to each other section, by means of which,

' switchboard. system a separate section of when desired, a connectionmade with an switchboard with springjacks having sepaanswering-jack of aline at one section of the rable switch-contacts, which, when the plugswitchboard, may be trunked to the 40 was inserted into the jack,disconnected from switchboard whereon is located the answerthe outgoingline-circuit the cables of the reing-jack of the line with which theconnecmainder of the switchboard, including the tion is to be completed,and may be made bridged line-annunciator, and connected with with thatanswering-jack. Under these cirthe springjacks on the other sections ofeumstances all cable and instruments will be 5 switchboard, alllong-distance connections disconnected from both lines of the completedwith lines being made at this section of the circnit,the result beingthen the exact equivswitchboard. alent of that obtained by the use ofthe It is the purpose of my present invention specialswitchboard-section before described. to perform the functions of thispeculiar sec- Of course this last mode of connection, by mo 50 tion ofswitchboard, while avoiding the large trunking from an answeringjack onone number of special spring-jacks contained in section to another on adifferent section of the switchboard, would be made use of only in thecase of long-distance connections, in which it might be necessary toleave the lines wholly free from attachments extraneous to thetelephone-circuit.

My invention, then, comprises, first, a telephone-line extending throughthe switchcontacts of a special answering spring-jack upon some sectionof a multiple switchboard and thence to a branch terminal spring-jackupon each other section of the switchboard, being closed finally througha line-annunciator, and, second, transfer-circuits or trunklines fromeach section of switchboard to every other section, by which a throughconnection may be made from any answering spring-jack on one section toan answering spring-j ack on any other section of the switchboard.

WVhen connection is made at-a single section of the switchboard betweenan answerin g-jack of the line terminating at that switchboard and theline-jack of anothcrline in the same section, the cabling and theline-annunciator of the call-initiating line are cut oil. When aconnection is made from an answer ing-jaok of, acall-initiating linethrough a trunk-line to another section of the switchboard, and therewith the answering-jack of the correspondent line, all switchboard-cableand both line-annunciatorsare removed from the circuit.

I have shown the arrangement of circuits of my invention in theaccompanying diagram. In this figure three sub-stations, A, B and G, arerepresented, furnished with the usual signaling and telephonicappliances. These stations are connected by lines, which are designated1 2, 3 4 and 5 6, respectively, with the apparatus upon three sections,(Z, d and d of amultiple telephoneswitchboard at a central station. Thetwo line conductors, l. 2, of line to station A, are connected with thecontact-springs of an answering spring-jack 6 upon sect-ion d of theswitchboard. This spring-jaek is of the type before mentioned-401ml; is,its switch-springs are separable from the contact-points upon which theynormally rest, and are opened from them when a plug is insertedinto thespring jack. From the contact-anvils of the springjack ca pair ofconductors 7 8 extend through the switchboard, being connected with thecorresponding line-springs in line springjacks e, c and e in thediii'ercnt sections of the switchboard, and with the main coil ofannunciator 6 which is located on the sectiond of the switchboard nearthe answeringjack .All the spring-jacks of the line have the usualtest-rings, which are connected together through a wire 9 and form aportion of a local circuit which is closed when connection is made withthe line, and which serves both to restore the line-annunciator whichhas been operated and to prevent its operation by subsequent signals inthe line. The

arrangement of circuits for this purpose is well known in the art.

The line conductors, 3 4, likewise extend through the switch-contacts ofan answeringjack f at section d of the switchboard, and thence to wires1O 11, which lead to the contact-sprin gs of spring-jacks f f f and tothe annunciator f on section d. The conductors of line to station 0 areconnected with answering-jack 9, line spring-jacks g, g and g and withannunciator g.

The wires 7 8, 10 11 and 12 13 are, in practice, made up into a cable.

Each switchboard is provided with pairs of connecting-plugs h h, eachhaving three contact-pieces adapted to register with the three contactparts of the spring-jack. The like line-contacts of the differentmembers of each pair of plugs are connected together by conductors 1e15, which constitute what is generally known as the plug-circuit. Aclearing-out annunciator dis connected in a bridge of this circuit.Those contact-pieces of the plugs which register with the test-rings ofthe spring-jacks form the terminals of a conductor 16, which is groundedthrough a battery 70. This battery serves to produce a test and also. toreset the line-annunciators.

A trunk-line is provided extending from each section of the switchboardto each other section, and terminating at each position in aspring-jack. Thus, trunk-line or transfercircuit 17 18 extends betweensections (1 and d of the switchboard, terminating in springjacks Z and Zat the different boards. Trunkline 19 20 extends between boards (1 and dand line 22 23 between boards. (1. and (1 For the purpose of tracing theopcrationof the system assume that subscriber at station 0 transmits aninitial call-signal by rotating his signaling-generator. The annunciatorg isoperated. and indicates the call to the opera tor at the section (1of the switchboard. This operator then inserts her answering-plug 72into the answering-jack g, learning the order from the subscriber bymeans of her telephone bridged across the plug-circuit in a well-knownway. By the insertion of plug h into the answering-jack g the conductors12 13 are disconnected from the line conductors 5 6, so that these lineconductors are left tree from all appended cables and from theshunting-magnet of annunciator 9 If the operator, having learned theorder, desires to make connection with the correspondent line at herown. section of the switchboard, she inserts plug it into the line-jackof that line-for example, into line-jack f if the call be for connectionwith station 15. This maybe done in case either or both of the lines areof low resistance and transmission between the stations is so good thatthe deleterious effect of the cable remaining attached to the line 3 4and the shunting effect of the line-annunciator f? are inappreciable.It, however, the connection required were with the station A, which maybe assumed to be so distant as to make telephonic communication with itdifficult, the operator may proceed in a different manner.

Having received the order for connection with station A, she will insertplug 71, into the trunk-jack Z, which forms the terminal of the transferor trunk circuit 17 18 to section d of the switchboard. She will then,by any suitable order wire or othercontrivance, such as are well knownin the art, instruct the operator at section cl to connect the trunkspringjack Zwith the answering-jack c. When this connection has beenmade, it will be noted that a complete metallic circuit will have beenformed from station to station A, be ing by way of line conductors 6,plug-circuit 14 15 at board d transfer-circuit 17 18, plug-circuit 14 15at board d, and line-circuit 1 2 to station A. The normal lineconnections of both lines, including the cable in the switchboard, theunused spring-jacks and the line-ann unciators will be cut off from thisthrough circuit at the answering-jacks g and 6, respectively. Thegreatest possible efficiency of transmission through the switchboardwill be thus attained.

I have not considered it necessary to show in detail the mechanism ofthe plug-circuit, or the signaling appliances for facilitating thetransfer of connections by means of the office trunk-lines. Variousmodes of performing all that is here required are well known in the art.

I claim as new- 1. The combination with a telephone-line, of a linespring-jack upon each of several sections of a multiple switchboard, andan answering spring-jack at one of the sections having contacts adaptedto be separated when a plug is inserted into the spring-jack andarranged to cut off the conductor extending to the line spring-jacks, asdescribed.

2. The combination with a telephone-line, of a line spring-jack uponeach of several multiple switchboards and an annunciator in a bridge ofthe circuit, and an answering-jack having separable contacts included inthe line-circuit between the sub-station and the line-jacks andannunciator, as described,

3. In combination,two telephone-lines,each extending normally throughseparable contacts in an answering-jack, and thence to line spring-jacksupon different sections of a multiple switchboard, connecting-plugsinserted in the different spring-jacks, and a loop-conductor completingthe circuit between the plugs, as described.

4. In combination,two telephone-lines, each extending normally throughseparable contacts in an answering spring-jack upon a section of amultiple switchboard, and thence to a signal-indicator in the samesection and to line spring-jacks on the different sections of theswitchboard, a transfer-line extending between the switchboards whereonthe answering-jacks are located, and means for connecting eachanswering-jack with the trunkline, whereby the telephone-lines may beunited in a through circuit devoid of appended line-jacks and signalinginstruments, as described.

In witness whereof I hereunto subscribe my name this 13th day of June,A. D. 1895.

CHARLES E. SORIBNER.

Witnesses;

ELLA EDLER, MYRTA F. GREEN.

